http://enn.com/news/enn-stories/2001/11/11272001/air_45660.asp - 11/27/2001 - ENN.com Clean air catalytic converters emit platinum pollutants
Tuesday, November 27, 2001 By Environmental News Network Catalytic converter The devices on cars that keep polluting emissions from reaching the air are spewing out other potentially toxic substances that are building up along U.S. roads. The culprits are catalytic converters. Mark Schneegurt, an assistant professor in biological sciences at Wichita State University, and a four person team from the University of Notre Dame have conducted one of the most comprehensive U.S. studies of roadside contamination by catalytic converters. Their study was published in a recent issue of the American Chemical Society's journal "Environmental Science & Technology." Catalytic converters have been used on U.S. cars since 1978 to turn toxic pollutants such as carbon monoxide and hydrocarbons into less harmful emissions through chemical reactions. The material used to speed up those reactions is filled with platinum, palladium and rhodium, known collectively as platinum-group elements or PGEs. Platinum group metals have been dubbed the noble metals because of their high resistance to oxidation and corrosion. These platinum-group elements are emitted as microscopic particles from a vehicle's tailpipe. The level and rate of PGE release vary according to how fast a vehicle is travelling and the type of engine that powers that particular vehicle. Enough platinum-group elements are being throw off from vehicles with catalytic converters that they are building up to potentially harmful levels along roadsides as far as 55 yards from the roads, the study showed. The researchers collected soil samples from urban roads and side streets in and around South Bend, Indiana, where Notre Dame is located. They also went to several sites along Interstate 80 between South Bend and Chicago, collecting roadside samples and soil samples at distances 16, 32 and 160 feet from the roadway. "There's so much of it that it's almost worth it to mine the top inch of roadside dust" for the three elements, said Schneegurt. Platinum is highly allergenic. If people are consistently exposed to certain allergens at even low levels they can develop allergies that can lead to asthma, or they can experience other symptoms such as sensitive skin. Not enough research has been done on palladium and rhodium to determine how harmful they are, Schneegurt said. PGE buildup could lead to other problems, considering a number of U.S. roads cut through agricultural areas, Schneegurt notes. It is not known if these elements are getting into groundwater supplies or the wildlife and human food chains. There is the potential for even more platinum-group elements to be emitted and in place far removed from highways. Catalytic converters must be attached to small gas engines such as those on lawn mowers and chain saws, according to the Clean Air Act of 1990. Schneegurt hopes the study will cause manufacturers to consider making changes to the converters. "Catalytic converters do far more good than harm, but we don't want to replace one problem with another," he said. Copyright 2001, Environmental News Network ------------------------ Yahoo! Groups Sponsor ---------------------~--> Universal Inkjet Refill Kit $29.95 Refill any ink cartridge for less! Includes black and color ink. http://us.click.yahoo.com/4bQK.B/MkNDAA/ySSFAA/FGYolB/TM ---------------------------------------------------------------------~-> Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Please do NOT send "unsubscribe" messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
